In the past years solid state disks have developed drastically and are now gaining increased popularity compared to conventional hard drives. While hard disk drives work predictable, transparent SSD routines work in the background without the user’s knowledge. This work describes the changes to the everyday life for forensic specialists; a forensic investigation includes data recovery and the gathering of a digital image of each acquired memory that provides proof of integrity through a checksum. Due to the internal routines, which cannot be stopped, checksums are falsified. Therefore the images cannot prove integrity of evidence anymore. The report proves the inconsistence of checksums of SSD and shows the differences in data recovery through high recovery rates on hard disk drives while SSD drives scored no recovery or very poor rates.

Computer security and privacy are becoming extremely important nowadays. The task of protecting computer systems from malicious attacks and potential subsequent catastrophic losses is, however, challenged by the ever increasing complexity and size of modern hardware and software design. We propose several methods to improve computer security and privacy from architectural point of view. They provide strong protection as well as performance efficiency. In our first approach, we propose a new dynamic information flow method to protect systems from popular software attacks such as buffer overflow and format string attacks. In our second approach, we propose to deploy encryption schemes to protect the privacy of an emerging non-volatile main memory technology - phase change memory (PCM). The negative impact of the encryption schemes on PCM lifetime is evaluated and new methods including a new encryption counter scheme and an efficient error correct code (ECC) management are proposed to improve PCM lifetime. In our third approach, we deconstruct two previously proposed secure cache designs against software data-cache-based side channel attacks and demonstrate their weaknesses. We propose three hardware-software integrated approaches as secure protections against those data cache attacks. Also we propose to apply them to protect instruction caches from similar threats. Furthermore, we propose a simple change to the update policy of Branch Target Buffer (BTB) to defend against BTB attacks. Our experiments show that our proposed schemes are both security effective and performance efficient.

Device Firmware Upgrade (DFU) is now widely used on PC and smartphones for users to enjoy the latest applications. The project is derived from the new device of Yohoo and the firmware embedded in the system. This system can guide users on how to breathe through multiple sensory effects to reduce the harm from excessive stress. In order to be applied by different people, some breathing courses and personal settings will be used in the system, which makes the upgrade of the internal firmware of the device more important. However, the firmware upgrade for some embedded devices is not as rapid and convenient as PC and smartphones, which is still erasing and then programming the whole storage. This is a waste of time and meaningless wear to the entire device. In order to solve this problem and improve the efficiency of the firmware upgrade, the partial firmware upgrade is proposed in this project, and the storage method of new codes is improved to get better performance during the partial DFU process. The idea of wear leveling is introduced to extend the lifetime of the internal storage. As a result, the partial firmware upgrade feature was successfully designed and implemented, and integrated and tested on new devices. At the end of this work, the prototype system of the embedded software based on the nRF52832 microcontroller has basically been designed, improved and tested, and some functions which need to be updated instead of the whole firmware can be transmitted via Bluetooth and work normally. For the specific case of partial DFU, the firmware package size that maximizes the update efficiency is obtained through testing. In addition, the flash module in the chip has been divided into multiple portions for the update. The wear-leveling method ensures that when a certain function is updated multiple times, one certain part of the flash will not be overused, but the entire block will be used uniformly to alleviate the adverse effects of data abnormality or loss caused by damaged bits of the flash memory. In addition, the lifetime of the flash memory is prolonged and the industrial waste is reduced at the same time. / Device Firmware Upgrade (DFU) används nu allmänt på PC och smartphones för att användare ska kunna njuta av de senaste applikationerna. Projektet kommer från den nya enheten till Yohoo och den inbyggda programvaran i systemet. Detta system kan vägleda användare om hur man kan andas genom flera sensoriska effekter för att minska skadan från för hög stress. För att kunna tillämpas av olika personer kommer vissa andningskurser och personliga inställningar att användas i systemet, vilket gör uppgraderingen av enhetens interna firmware viktigare. Firmwareuppgraderingen för inbäddade enheter är dock inte lika snabb och bekväm som PC och smartphones, som fortfarande raderar och sedan programmerar hela lagringsutrymmet. Detta är slöseri med tid och meningslöst slitage på hela enheten. För att lösa detta problem och förbättra effektiviteten för uppgradering av firmware föreslås partiell uppgradering av firmware i detta projekt, och lagringsmetoden för nya koder förbättras för att få bättre prestanda under den partiella DFU-processen. Idén om slitstyrning införs för att förlänga livslängden för den interna lagringen. Som ett resultat designades och implementerades delvist firmware uppgraderings funktionen och integrerades och testades på nya enheter. I slutet av detta arbete har prototypsystemet för den inbäddade programvaran baserat på mikrokontrollern nRF52832 i princip utformats, förbättrats och testats, och vissa funktioner som måste uppdateras istället för hela firmware kan överföras via Bluetooth och fungera normalt. För det specifika fallet med delvis uppgradering erhålls firmwarepaketets storlek som maximerar uppdateringseffektiviteten genom testning. Dessutom har flashmodulen i chipet delats upp i flera delar för uppdateringen. Slitstyrningsmetoden gör att när en viss funktion uppdateras flera gånger kommer en viss del av blixt inte att överanvändas, men hela blocket kommer att användas enhetligt för att lindra de negativa effekterna av data i normalitet eller förlust orsakat av skadade bitar av flashminnet. Dessutom förlängs flashminnets livstid teoretiskt och industriavfallet minskas samtidigt.